Data from: A comparison of image statistics of peacock jumping spider colour patterns and natural scenes

The form of arbitrary sexual signals may be driven by the need to be
detectable against the background or, alternatively, by selection for
efficient processing by the nervous system. This latter alternative is a
prediction of the sensory drive hypothesis extended to include efficient
coding as a driver of the form of sexual signals. This hypothesis posits
that animal visual systems are adapted to process the visual statistics of
natural scenes, and that easily-processed stimuli induce a sensation of
pleasure in the viewer. In support of this, natural scene statistics have
been found to be preferred not only by humans, but by the peacock spider
Maratus spicatus. Here we test if male peacock spiders of the highly
sexually dimorphic Maratus genus generally (a) evolve colour patterns with
image statistics that contrast with the natural background or (b) exploit
a potential processing bias by evolving colour patterns with visual
statistics similar to those of natural scenes. We analyse and compare
multispectral images of male and female spiders of 21 Maratus species and
of natural scenes similar to the spiders’ habitat. We find that the image
statistics of male patterns diverge from those of natural scenes, whereas
the statistics of female patterns do not. Our results support the idea
that colour patterns evolve contrasting image statistics to increase
conspicuousness and matching image statistics to be camouflaged. Any
processing bias for natural scene image statistics in Maratus thus appears
to play little role in the evolution of their sexual signals.